(a) Field of the Invention
The present invention relates to an APS (Advanced Photo System) camera, more particularly to apparatus and method for moving a film in an APS camera.
(b) Description of the Related Art
Generally, a conventional 35 mm camera uses 35 mm having perforations formed on both edges of the film. Each frame of the film has eight perforations on both edges, and loading and transporting of the film is controlled according to the number of perforations detected.
In a conventional camera, when the shutter release button is pressed by a user, one frame of the film is exposed. After exposure, the film is transported across a shutter region of the camera. Perforations on the edge of the film are detected by perforation sensors and counted by a counter. When the counter counts a total of eight perforations, the controller determines that film transport is complete and stops the film transport, thereby placing the next frame in position for exposure.
In an APS camera conventional 35 mm film is not used. Rather, as shown in FIG. 2, film 5 for an APS camera has only two perforations, 6 and 7, which are formed along a single edge of the film. The first perforation 6 is formed at a position indicating the start position of a frame 8 and the second perforation 7 is formed at a position indicating the end position of the frame. Once a frame of the film 5 is exposed at the shutter region, the exposed film is transported and generally wound around a take-up spool. After sensing the first perforation, the film transport stops when the second perforation 7 is sensed by a perforation sensor 10. If the perforation sensor 10, or advancement motor (not shown) of the camera transport malfunctions during transporting of the film, the exposed film will not be transported completely. Therefore, taking another picture would cause the exposed film to be exposed again or at least cause overlappingexposed images.
With reference to FIG. 5, a method of solving the above problem is described. The amplitude of an output signal 12 from the perforation sensor changes each time a perforation is detected during film transport. When an error occurs during transporting of the film, between the first perforation 6 and the second perforation 7 of a frame(section x), transport of the film stops at the first beginning perforation of the immediately succeeding frame (designated by point A).
On the other hand, when an error occurs during film transport between second perforation 7 and a first perforation 6 of an immediately succeeding frame(section y), transport of the film is performed so that the next frame is skipped and transport is stopped at a first perforation of the next frame (at point B)resulting in a wasted frame.